1997 chevy silverado wont start

You may not be burning fuel correctly. Check the plugs if they are producing sparks while running. You can pull it one by one while the engine is running. If after pulling the plug, the motor should sound different or would have difficulty running if this does not happen then most likely the cylinder where you pulled out the plug may the source(s) of the problem Check out the sparks if there are any on that plug and have the spark plug checked out. There may be problems with the distributor that is why it is not delivering the proper spark to the plugs or the ignition system may be bad. Also check the fuel lines if they are clogged. If you have as scanner, have the ECU scanned for errors that may have been detected by the system.